After reportedly scuttling plans to build a new 1.9 million square foot tower in Battery Park City, Goldman Sachs is now looking around for a midtown alternative, according to the New York Post. The only problem, say insiders, is that another alternative in Manhattan may not exist: "Try finding a site than can immediately accommodate a nearly 2 million square-foot tower." For now, Plan B appears to be something along the lines of the Hotel Pennsylvania site on Seventh Avenue at 33rd Street -- but that would require demolishing the hotel and then designing and building a super-skyscraper from scratch. That's doable, of course, but Goldman needs a new HQ by 2008, when a number of downtown leases are set to expire.